Plate Tectonics
A:
The three types of plate boundaries are divergent plate boundaries, convergent plate boundaries and transform plate boundaries. Divergent plate boundaries occur in places where two plates are moving away from each other. When two plates are being forced together, they are called convergent plate boundaries. Finally, transform plate boundaries occur in places where two plates are moving in opposite directions and rubbing against each other.
-
Q: What causes tectonic plates to move?
A: The three primary causes for tectonic plate movement are the convection of material in the mantle, gravity and the rotation of the planet. These forces cause each of the seven major plates and numerous other microplates to move independently of the others at a rate of a few centimeters per year. -
Q: How far do tectonic plates move each year?
A: Earth has between 10 and 20 crustal plates, each moving at a different rate. The slowest is the Eurasian plate, which moves less than an inch per year, while the plate with fastest known movement is the Cocos plate, which grinds against the west coast of Central America at an estimated 8.55 inches per year. -
Q: What kinds of plate boundaries are there?
A: The three types of plate boundaries are divergent plate boundaries, convergent plate boundaries and transform plate boundaries. Divergent plate boundaries occur in places where two plates are moving away from each other. When two plates are being forced together, they are called convergent plate boundaries. Finally, transform plate boundaries occur in places where two plates are moving in opposite directions and rubbing against each other. -
Q: What type of plate boundary does the San Andreas Fault exemplify?
A: The San Andreas Fault exemplifies a transform fault plate boundary. Transform fault boundaries consist of two plates sliding against each other in a horizontal motion. -
Q: What is the San Andreas Fault?
A: According to SanAndreasFault.org, the San Andreas Fault is a commonly known fault partly because of the disastrous 1906 San Francisco earthquake. The site explains that it also passes through California, which is often in the news because of earthquakes that occur along this fault. -
Q: What causes continents to move across the Earth's surface?
A: Tectonic activity causes continental drift to occur on the Earth's surface. National Geographic explains that continents rest upon massive slabs of rock called tectonic plates. Over the course of millions of years, tectonic activity shifts these plates and rearranges the accompanying landmasses. -
Q: What direction is the Eurasian plate moving?
A: The spreading seafloor of the Mid-Atlantic Ridge serves to push the Eurasian Plate east in relation to the neighboring North American Plate it borders. Continents and landmasses rest atop 14 massive tectonic plates that shift and move in various directions. -
Q: What is the definition of plate boundaries?
A: Plate boundaries are locations where two tectonic plates meet. There are three different types of plate boundaries, which are defined by the type of motion occurring at the boundary. Some boundaries are located within continents of land, while others are located under oceans. -
Q: What happens in deep ocean trenches?
A: According to Science Daily, the most significant geological event that happens in ocean trenches is the gradual subduction of the Earth's crust down into its mantle. This process takes tens of millions of years. -
Q: What drives plate tectonics?
A: The plate tectonics theory suggests that the outer shell of the Earth's surface is split into a few plates that move along the mantle, forming a hard shell, with pressure from mid-ocean ridges and subduction zones causing the shifting in the plates. Mid-ocean ridges are the gaps that lie between the plates, much like the seams on a basketball. Magma oozes through these ridges, creating new crust on the ocean floor and pushing the plates apart, while subduction zones sit at the meeting point between plates. One slides under the other, pulling the crust down as it goes. -
Q: What is the difference between continental drift and plate tectonics?
A: Plate tectonics is the theory that explains the structure, composition and internal workings of the Earth on a worldwide scale, while continental drift refers to the theory that the continents all used to be connected in one megacontinent which scientists dub Pangaea. Both theories attempt to explain the movement of parts of the Earth's crust. -
Q: What is the "earth fault current"?
A: Earth fault current is a current that flows directly from phase conductors to earth. It may also refer to a current that flows from protective conductors from the point of an insulation breakdown. -
Q: How can plates move apart at the mid-ocean ridges and not leave a deep gap in the lithosphere?
A: According to the National Oceanographic and Atmospheric Administration, the reason the divergent plate boundaries at mid-ocean ridges don't result in gaps in the Earth's crust is that when the plates move apart, they allow magma to well up from beneath and form new rock. At each of these ridges, new ocean floor is created constantly, filling in any potential gaps. -
Q: Why do earthquakes and volcanoes happen mostly in the same place?
A: Earthquakes and volcanoes occur in the same places because they both happen along the Ring of Fire. The Ring of Fire is located along the edges of a major tectonic plate. -
Q: Where is the most active plate boundary?
A: The most active plate boundary is in the Pacific Ocean basin. Several tectonic plates collide in this area, which is known as the Ring of Fire due to the high number of volcanoes, earthquakes, deep sea trenches and other seismic activities occurring on its rim. -
Q: What does plate tectonics mean?
A: According to About.com, plate tectonics is the scientific theory that attempts to explain the movement of the Earth's lithosphere, which has formed the landscape features seen across the globe. It provides geology with a comprehensive theory that explains how the Earth works. -
Q: How many tectonic plates are there?
A: There are seven major tectonic plates on the planet that are further subdivided into dozens of smaller plates. Geologists do not always agree on how to subdivide the minor plates. Each plate is in motion relative to the other plates. -
Q: What is some evidence of plate tectonics?
A: According to the Physics Department of the University of Tennessee Knoxville, evidence for plate tectonics has been found by studying continental shapes and comparing fossils. It notes that modern evidence for plate tectonics is much stronger than when it was first offered as a theory. -
Q: What drives the process of plate tectonics?
A: Very slow currents in the relatively plastic lower mantle, or aesthenosphere, are thought to push the crustal plates along and drive the process of plate tectonics. These currents are caused by convection, with the mantle rock being heated from below via radioactive decay and thus becoming less dense than the rock above. These hotter rocks move slowly upward, displacing the rock above and forcing it down in an elliptical motion. -
Q: What is the world's biggest fault line?
A: The world's biggest fault line is the San Andreas Fault. The fault extends more than 800 miles northwestward from the Gulf of California through the state and into parts of the Pacific Ocean. -
Q: What form of geological activity does the Great Rift Valley represent?
A: The Great Rift Valley of East Africa represents Earth’s tectonic activity. According to Geology.com, the tectonic forces active at the site are trying to tear up old tectonic plates to create new ones.
